Some remote sensor devices are capable of communicating a signal to a primary device indicating when the remote device is low on power. Upon receiving such a signal, the primary device may warn its user that the remote device is low on power, and thus enable the user to recharge or replace the battery of the remote device before the remote device actually runs out of power. One example of such a system is a computer that employs wireless user input (UI) devices, such as a wireless mouse or keyboard. When such UI devices are low on power, a signal is communicated to the computer's processor indicating the low power condition, and the computer then displays a message to the user warning of the same. If the user subsequently fails to replace or recharge the battery promptly, the remote device continues to operate normally until it has completely run out of power. At such time, the remote device becomes incapable not only of performing its intended function but also of informing the primary device of the reason it has become inoperable.